A.7 Grammar
There are no commas in the SELECT list. This looks like a poor
design because it will be an obstacle to allowing arbitrary
expressions in the SELECT list in a future version. I asked for
arbitrary expressions in a previous round of comments, and was told
that this was being deferred to the future. That is fine, but I want
to insure that the ground is ready for that extension.
Strictly speaking, commas may be unnecessary since SELECT ?a ?b + ?c
can be parsed. The issue is that this is not very friendly to the
user because having commas to separate expressions is an opportunity
for the parser to catch typos. I note that our syntax for
function calls requires commas between successive expressions, even
though there too they are not strictly necessary.
ORDER BY also lacks commas, so if we add them to SELECT we
should probably add them to ORDER BY.
Fred